The Neotropical land snails (Mollusca, Gastropoda) collected by the ‘Comisión Científica del Pacífico’

The land snails collected by the ‘Comisión Científica del Pacifíco’ (CCP), a Spanish expedition to South and Central America from 1862–1866, are restudied and revised. The historical context of the expedition and the study of its collected material are described. Biographical data is given for the main persons involved. The land snails were previously studied by Joaquin Hidalgo between 1867 and 1893. A total of 3,470 specimens belonging to 211 species are treated in this paper. Of 34 species mentioned by Hidalgo is his catalogue, the corresponding material could not be located. Bulimus visendus Hidalgo, 1869 is now placed in the genus Synapterpes Pilsbry, 1896, a new combination.


INTRODUCTION
On the 10th August 1862, a group of Spanish scientists sailed away from Cadiz for an expedition that would last until the 18th January 1866. This group of men, known as the 'Comisión Científica del Pacifíco' (CCP), would visit many parts of South, and some parts of Central, America and collected many specimens of animals, artefacts and plants and made photographs and illustrations of the remarkable things they observed (Barreiro, 1926;Miller, 1968;Puig-Samper, 1988;Calatayud, 1994;López-Ocón, 2003). The group (Fig. 1) consisted of Patricio Paz y Membiela (zoologist and president of the CCP), Manuel Almagro y Vega (anthropologist and ethnographer), Fernando Amor y Mayor (geologist and entomologist; vice-president), Francisco de Paula Martínez y Sáez (zoologist), Marcos Jiménez de la Espada (zoologist), Rafael Castro y Ordóñez (photographer and draftsman), and Juan Isern (botanist). The taxidermist Bartolomé Puig y Galup was selected shortly before their departure, but left the CCP in autumn 1863 whilst in Chile. The land molluscs, which were mainly collected by Paz y Membiela and Martínez y Sáez (see below), were studied by Joaquin González Hidalgo who published an extensive catalogue with supplements (Hidalgo, 1870;Hidalgo, 1875;Hidalgo, 1893a;Hidalgo, 1893b).
This study of the molluscan part of the CCP material deserves to be placed in its historical context to understand several details that will be discussed below. In the section 'context of the collection' we will therefore briefly elaborate on the creation of the CCP, its itinerary, the way the study of its collected material was undertaken and the results that were published. We will also present biographical data on relevant CCP members and the persons directly involved in the study of the land molluscs. Until now, the full extent of the CCP collection of land molluscs was not precisely known, as Almagro (1866) presumably only gave numbers of the material which was exhibited to the public in 1866, and Hidalgo listed only the species recognised without mentioning any numbers. A partial summary, listing only the new species described by Hidalgo, was given by Calvo (1994). The recent discovery of an undescribed species which appeared to be mixed in with other material (Breure & Araujo, 2015) stimulated this current study, which aims to revise all of the known land mollusc material collected by the CCP.
Fernando Amor y Mayor (1822-1863; hereafter: Amor) finished his studies of pharmacy in 1845 in Madrid, and became full professor in the Institutes of Cuenca, Córdoba and Valladolid. He had good contacts with Mariano de la Paz Graells, who was MNCN director from 1851 and one of the scientific advisors of Queen Isabel II. Amor travelled in Morocco during 1859, probably associated to a military expedition to explore the future territory of the Spanish war in Morocco (Barras de Aragón, 1949;Puig-Samper, 1988). In 1862 he was designated as a member and vice-president of the CCP, and entrusted with geology and entomology. He died in San Francisco during the expedition possibly due to a disease contracted in the Atacama desert (Perejón, 2012). He wrote a diary, probably lost in the fire of the ''Triunfo'', the ship on which the CCP travelled during the expedition. Part of this diary was saved by Barreiro (1926).
Francisco de Paula Martinez y Sáez (1835-1908; hereafter: Martinez, Fig. 4), finished his studies of natural sciences in 1857 in Madrid, and worked at the MNCN entrusted with the collections of vertebrates. He was professor of mineralogy and botany at the Central University in Madrid during 1861-1862, and full professor of natural history in the institute of Teruel. In 1862 Martinez was designated as member and secretary of the CCP (Gogorza, 1908). He was entrusted with aquatic mammals and reptiles, fishes, crustaceans,  (Tual & Fischer, 1899).
Marcos Jiménez de la Espada (1831-1898) studied natural sciences in Madrid and in 1853 worked at the Central University. From 1857 he worked in the collections of the MNCN until his designation as member of the CCP for geological, zoological, anthropological, ethnographical, botanical and geographical studies. Although he was a disciple of Graells, Espada was rather critical about the organisation of the Commission (Puig-Samper, 1988). He published 'Vertebrados del Viaje al Pacífico, Batracios' (Jímenez de la Espada, 1875).
We will end this section with biographical data on persons who, although not members of the CCP, are important in the rest of this study. In Madrid two persons were related to the material collected by the CCP, Joaquin Hidalgo and Florentino Azpeitia. Abroad, only a few malacologists were entrusted with descriptions of part of the new species among this material, Hippolyte Crosse, Louis Pfeiffer and Rudolph Philippi.
Joaquin G. Hidalgo (1839Hidalgo ( -1923Fig. 7) studied medicine in Madrid at the San Carlos Hospital, and afterwards natural sciences at the Central University. He started with an interest in Mineralogy but decided to finalise his study in medicine on the advice of his professor Rafael Martinez y Molina; he graduated in 1861 and settled in Madrid as a medical doctor. Nevertheless, he began in these years with his collection of shells and his first naturalistic travels within Spain subsidised by Pedro González de Velasco (1815-1882, who worked at the San Carlos Hospital. In 1860 he came into contact with the military Patricio Paz y Membiela in Barcelona and together they worked on his extensive malacological collection. This was probably the reason why in 1862 Paz invited Hidalgo to become a  (Wheeler, 1949); (B) Rudolph Philippi, unknown date (CCHS-CSIC). member of the CCP as a naturalist; an offer which Hidalgo declined because of his medical practice. In his place Martínez became member of the Commission. During 1862 and 1875 Hidalgo gave classes at the Central University in zoology, mineralogy and botany. He travelled to Paris in 1865 and 1868, where he was in contact with Deshayes, Crosse and Fischer. Hidalgo had also relationships with Gassies, Souverbie, Guestier, Morelet, Morlet, Jousseaume, Fischer Jr., Dautzenberg, Dollfus, de Folin, Petit de la Saussaye, and Locard. We have found two documents compiled by Hidalgo that lead us to suggest he was sensitive to the opinions of others about his work. The first [Enumeración: MNCN Library F-II-5727] listed the comments of foreign colleagues as published in their own work (if not in French, translated into Spanish); the comments are mainly from Crosse, with additional ones from e.g., P. Fischer, Jeffreys, Dautzenberg, Kobelt, Pfeiffer, and Drouët. The second document (Hidalgo, 1918?) [Relación: MNCN Library F-II-5737] gives an overview of excerpts (translated in Spanish) of 47 correspondents who wrote favourable sentences about his work in letters addressed to Hidalgo. Although, unfortunately, the correspondence of Hidalgo has not been located, this document was used for a partial reconstruction of his network (Breure & Backhuys, 2017). Both documents had been printed and were apparently primarily aimed at Spanish readers. Hidalgo published his malacological manuscripts in the Journal de Conchyliologie, the Real Academia de Ciencias Exactas, Físicas y Naturales de Madrid, and the Sociedad Española de Historia Natural founded by Velasco, Martinez Molina and Zapater. Importantly, Crosse and Fischer helped Hidalgo in the drawing and publication of the plates of his manuscripts. In 1867 he published his first catalogue of Spanish marine molluscs. Afterwards, he published the books on the CCP molluscs with the plates made in Paris (see below). Thanks to Graells, in 1877, Hidalgo was admitted to the Real Academia de Ciencias Exactas, Físicas y Naturales and at the MNCN. He worked again at the University between 1888 and 1897 in botany, mineralogy and zoology, and in 1897 became full professor of mineralogy. He was also involved with the mineral collection at the MNCN. In 1900 he changed the professorship of mineralogy for one in molluscan zoogeography. Hidalgo was director of the MNCN from 3 July 1900 to 2 July 1901 (Barreiro, 1992: 301, 309). He donated his malacological library (c. 2,000 publications) and sold his shell collection to the MNCN in 1913 (Barreiro, 1992: 321, 455-457). In summary, he published 7,600 pages on malacology with 336 plates (made by Arnoul, Delahaye, Laporta and Arroyo) (Hidalgo, 1913?); a bibliography was published by Azpeitia (1923). Florentino Azpeitia Moros (1859-1934Fig. 8) was professor of geology and paleontology in the Escuela Especial de Ingenieros de Minas in Madrid. He was friendly with Hidalgo since 1883, when Azpeitia was treated by Hidalgo as a medical doctor because of gastric fever. From this point, the two men worked together on malacology, Hidalgo being the master and Azpeitia the disciple. He became member of the Sociedad Española de Historia Natural in 1897 for his studies in molluscs and diatoms. Azpeitia was the author of numerous scientific works on geology, botany and zoology; some of the most importance were his 'Monografía de las Melanopsis vivientes de España ' (1929) and 'Conchas bivalvas de agua dulce de España y Portugal ' (1933' ( ) (Álvarez Halcón, 1997Álvarez Halcón, 1998). His molluscan collection, with 80,000 specimens of 8,171 species (6,594 gastropods and 1,577 bivalves) was donated to the MNCN in 1934 (Barreiro, 1992: 342).
Hippolyte Crosse (1826Crosse ( -1898Fig. 9) studied law, but had an interest in natural history from a young age. After a trip to southern France, Corsica and Sicily in 1849, he devoted himself totally to malacology. The Journal de Conchyliologie had been established in 1850 by Petit de la Saussaye, but ceased to appear after a few years. In 1856 it was resurrected by P. Fischer and A.C. Bernardi, and in 1861 Crosse joined them, soon becoming managing director. Together with Fischer he made the journal one of the outstanding malacological journals of the late 19th century (Poyard in Poyard et al., 1898?: 3-6). As managing director he was in contact with all the major malacologists of the era, and received many type specimens of species published in the journal (Fischer-Piette, 1950). From his extensive correspondence with Hidalgo, we know that he also regularly received specimens of CCP material for his own collection, which was auctioned after his death (Breure & Backhuys, 2017;Tual & Fischer, 1899). Louis Pfeiffer (1804Fig. 10) studied medicine at the Universities of Göttingen and Marburg, after which he did postgraduate work in Paris and Berlin. In autumn 1826 he settled in his city of birth Kassel to practice medicine. After his first marriage in 1833 he gave up his medical practice and devoted himself to botany and malacology, making extensive excursions through Germany and the Low Countries. In 1838-1839 Pfeiffer made a trip to Cuba, together with Johannes Gundlach, which had a significant bearing on his future work. After his return to Germany he received further Cuban shells from Gundlach and Felipe Poey. Pfeiffer made frequent trips to Paris and London to consult literature not accessible in Kassel and to study the collections brought to Europe by the great French voyages, and especially those of Hugh Cuming in London. After the death of his youngest son during the Franco-Prussian war in 1870 his health was much impaired (Wheeler, 1949). Rudolph Philippi (1808-1904Fig. 11) was sent at a young age to Switzerland to have private education by the renowned Swiss philosopher Pestalozzi. He soon became interested in the flora and fauna, but graduated as a Doctor of Medicine in Berlin in 1830. During a visit to southern Italy in 1831-1833 he studied the molluscs and the geology of the region. In 1835 he got a position as professor at the Polytechnic Institute of Kassel. Soon afterwards he suffered from health problems and returned to Naples from 1837-1839. Due to the unstable political circumstances he decided to emigrate in 1850 and was appointed as professor of German in Valdivia, Chile. In 1853 he became director of the Museo Nacional de Historia natural in Santiago, as well as professor of botany and zoology at the University. In 1854 he was rejoined by his family, which also brought his library and scientific collections to Santiago. He made important contributions to the knowledge of the flora and fauna of Chile (Emig, 2015). On the 18th May 1863 the CCP members met with Philippi in the Santiago museum and they revised collections in the museum, made an excursion together with Philippi and their visit ended with a banquet on the1st June (Blanco, Rodríguez & Rodríguez, 2006: 112-114). Philippi named several species of plants and molluscs after CCP members (this study ;Blanco, Rodríguez & Rodríguez, 2006: 264).

The 'Comisión del Estudio de collecciones del Pacifico'
When in 1868 in Spain a new, liberal government came to power that wanted to promote science (López-Ocón, 1997), attention for the CCP material was renewed after it had wained following the exhibition in 1866. A 'Comisión de Estudio de las collecciones del Pacifico' (CEcP) was established that aimed to study the materials collected by the CCP and publish the results. At its start on 14 January 1868, the CEcP consisted of Francisco Méndez Álvaro (president), Juan Villanova y Piera (vice-president), Francisco de Paula Martínez y Sáez (secretary), Manuel Almagro, Manuel de Galdo, Joaquin Hidalgo, Marcos Jiménez de la Espada, Sandalio Pereda, José Solano y Eulate, and Lucas de Tornos. In April 1868 the Ministry of Public Instruction asked for the completion of their task as soon as possible (Blanco, Rodríguez & Rodríguez, 2006: 260). The CEcP members complained about the short notice given and argued that they needed several years to produce good scientific results. They even recommended they should travel to several European countries for their studies. The minutes of the Committee, however, show that the study of the material did not  progress very smoothly [Archive MNCN CN0042/755/001]. The members of the CEcP soon discovered that they lacked the literature to identify the material, and Hidalgo made a list of desired malacological publications. The list comprised 34 books and two journal series, covering all the important malacological works since the beginning of the 19th century [Archive MNCN CN0041/749/015]. Ten of these books, however, did not or only partially reached the CEcP [Archive MNCN CN0041/749/016]. Besides the new scientific books, these minutes of the Committee showed that the CCP material had generally been split into two collections, of which one was retained for the MNCN, and one was to be sent to other schools, institutes and Museums; we have found no information about the latter. During the Spanish revolution and the abdication of Isabel II in the Autumn of 1868, Méndez Álvaro and José Solano were ousted and the former replaced by the new President M. M. J. de Galdo. In November 1868 the new Committee decided to entrust to Martínez, Jímenez de la Espada and Hidalgo the elaboration of scientific papers on the CCP material to be published in 1869. The outlines for these scientific 'Memorias' were accorded by the CEcP members in June 1869. In November 1869 the Commission apparently had received some money from the Ministry, which they decided to spend partly for these publications (see also Breure & Backhuys, 2017). The minutes of the CEcP end with this meeting, suggesting less organisational activities in 1870 [Archive MNCN CN0042/755/001]. During that year, again as a result of political changes, President Galdo was replaced by Lucas Tornos. By order of the Ministry (Ministerio de Instrucción Pública) the CEcP was dissolved on the 1st August 1872 providing that the director of the MNCN would be dealing with all the zoological material from the CCP. Galdo protested against this dissolution and, after another political change, the members of the Committee were re-installed by the new Government in May 1873. However, work on the scientific publications stopped and the CEcP was again dissolved on the 30th June 1875. The zoological CCP material arrived to the MNCN in 1880 (Puig-Samper, 1988: 351-352).
It is likely that Hidalgo already started working on CCP material before this time, resulting in his 1867 paper. This may explain the 'flux' of the material: from Paz to Hidalgo to Azpeitia's collections; we also found some specimens in the 'Coll. Graells' (i.e., historical collection of MNCN) which may have been used for exhibitions over time and which may have originated from the CCP material. Following Almagro (1866), who recorded the data for the exhibition of the CCP material in the Jardín Botánico, the collection of molluscs from the CCP comprised 816 different species, and 38,755 specimens, collected mainly by Paz and Martinez, and some by Jiménez de la Espada, Isern and Almagro. There were also 767 specimens belonging to 43 species of molluscs that had been be-gifted by Barreiros, Jameson, Philippi, Richardson, and Zameron. Grouped in another way, 741 specimens of marine bivalves, 300 of freshwater bivalves, 2,117 terrestrial gastropods, 1,277 freshwater gastropods and 2,557 marine gastropods were collected. There were also 975 specimens in 117 jars of alcohol preserved material, as was stipulated in the instructions for the expedition made by Graells (Puig-Samper, 1988). In 1868 and 1869 the collections of duplicate specimens were sent to several Spanish universities and institutes. In 1880 all the material collected by the CCP was moved to the MNCN (Puig-Samper, 1988). More detailed information on the localities and sources of the molluscs collected can be found in Puig-Samper (1988) and Calatayud (1994), and will be given below for the land molluscs.

The Mollusca collected by the CCP
All the Mollusca specimens of the CCP were studied by Martinez, who was responsible for molluscs during the expedition, and by Hidalgo (1893aHidalgo ( , 1893b, with the exception of the freshwater bivalves that were studied by Lea (1866aLea ( , 1866bLea ( , 1867Lea ( , 1869aLea ( , 1869b and Haas; Haas, during his forced stay in Spain due to the unfavourable political climate in Germany (Haas, 1915), was invited to the MNCN where he studied the mussels collected by the CCP (Haas, 1916). Hidalgo and Martinez wrote the three volumes of the 'Moluscos del viaje al Pacífico', which included terrestrial gastropods (Hidalgo, 1872), marine bivalves (Martínez, 1879?), and marine gastropods (Hidalgo, 1879). There has been some confusion in the literature about the dates of publication, especially about the first part. Both the first and second parts have the date '1869' printed on the title page, and this has generally been accepted by subsequent authors. The first part was published in Madrid by Cárlos Bailly-Baillière. The second and third parts bear the inscription on the title page 'Imprenta de Miguel Ginesta'; the final volume appeared in 1879, and this date has been undisputed. As we know (Breure & Backhuys, 2017), the plates for the first and second part were executed in Paris and delivered in Madrid in November 1871. The text for the first part, however, still had to be finished by Hidalgo and this volume did not appear before December 1872. Hidalgo himself was aware of the potential problem of the discrepancy between the date on the title page ('1869') and the actual publication date. He inserted at the end of the text a 'Note' to draw attention to this discrepancy (Hidalgo, 1872: 152): Nota. No concluida de imprimir la presente parte hasta 1872, esta es la verdadera fecha de publicación de nuestro libro y no la de 1869 que figura en la portada. Si el Gobierno de S. M. facilita medios necesarios para la impresión, ejecución de láminas, etc., del resto de la obra y si se nos indemniza del tiempo invertido en este trabajo, que hemos hecho sin sueldo ni gratificación alguna, daremos á conocer á nuestros lectores las demás especies de Moluscos recogidas por los naturalistas de la Comisión científica española.
[Note. Not having finished the print of the present part until 1872, this is the true date of publication of our book and not 1869 as contained in the cover.
If the Government will provide the necessary means for printing, execution of plates, etc., [for] the rest of the work, and if we are indemnified [for] the time invested in this work, which we have done without any payment, we will disclose to our readers the rest of the species of molluscs collected by the members of the CCP] This note means that the book of Martinez was not yet published in 1872 and, as Breure & Backhuys (2017) have shown, the actual date of publication was much later; it was published in 1879 or even later.
Finally, it should be remarked that not only in the publications of Hidalgo, but also of others (notably Crosse), the suggestion was given that much of the CCP material was collected by Paz. This was only true in the cases where Paz actually visited the region; in other cases, after his premature return to Spain, Paz did not even visit some of the localities (e.g., Ecuador) but the material became nevertheless part of his collection or was misleadingly referred to as having been collected by him.

Labels and handwriting
The material was found with labels that allowed its provenance to be ascertained, in most cases, unambiguously. The labels from the former Collection of Paz are characterised by a red frame; their locality data is usually more general than the data which has been published for the lot. The handwriting of these labels is in Hidalgo's hand. One clear exception is a lot where the original label in the handwriting of Paz has very specific locality data, while only a very generalised locality has been published by Hidalgo. Compare Figs. 7A-7B for examples of handwriting of Paz and Hidalgo. In most cases, the labels bear the annotation ''Cat. Am. mer. no. XYZ''; this refers to the catalogue published by Hidalgo (1870), which totalled 201 species (Hidalgo, 1870), increasing to 242 species (Hidalgo, 1893a;Hidalgo, 1893b). Labels from lots collected by Martínez bear his name and generally have a more precise locality; they all formed part of the former collection of Hidalgo. However, the handwriting is written in a hand unknown to us. In the former collection of Azpeitia the labels are small and Azpeitia's handwriting (Figs. 8G-8H) was very fine and clear. Some labels had been glued to the shells, and generally this has been maintained with the addition of a modern label. In a few cases the original labels have been lost, and all the data is from modern labels. Generally, Azpeitia copied the localities from the data published by Hidalgo. Figure 8 gives an overview of all the styles of labels associated with the CCP material.

Remarks.
The numbers between square brackets following the taxon names refer to Supplementary file 1, column 'nr.' available on Figshare: https://doi.org/10.6084/m9. figshare.4231904.v1. For the species described as new from the CCP material the etymology is added in the case of eponyms. Etymology. Named after Patricio Paz y Membiela.

Remarks.
Of the three specimens the one figured herein seems to have been collected rather fresh and, although the peristome is unexpanded, seems to exhibit the features of this species the best. One specimen was found with locality data ''Napo (Ecuador)'', Coll. Hidalgo ex Martínez, MNCN 15.05/7214, identified as this species, which appeared to be a specimen of Plekocheilus (Eudolichotis) distorta (Bruguière, 1792). This was likely not material collected by the CCP, as this species occurs in northern Venezuela; this region was not visited by the CCP.  (Breure, 1978: 16).

Remarks.
From the labels and further information from the correspondence between Hidalgo and Crosse (Breure & Backhuys, 2017), it may be inferred Hidalgo had two specimens when he was making the Catalogue of the CCP material (Hidalgo, 1870). One specimen was sent to Crosse for description and returned to Hidalgo; both specimens are considered as belonging to the original series. The specimen from the Azpeitia collection undoubtedly originates from Hidalgo, but is not considered as type material since it cannot be ensured it was already in his possession during 1869.

Genus Sultana Shuttleworth, 1856
Orthalicus ( (Calatayud, 1994: 268).    (Ancey, 1890) has been reported from Ecuador without specific locality (Breure & Mogollón, 2016). These authors also reported a record for the nominate taxon from the Chanchamayo valley. In any case, there is no evidence this material was collected by Almagro, who has not travelled in Peru in areas where this species does occur. If the label ''Ecuador'' has to be trusted, it is likely this specimen was collected on the eastern slopes of the Cordillera.

Remarks.
Only the smaller specimens from the series identified by Hidalgo seems to correspond with this species. However, the transition to Bostryx modestus (Broderip in Broderip & Sowerby, 1832) seem to be gradual and future research may prove these two taxa to be synonyms.

Genus Bulimulus Leach, 1814
Bulimulus Leach, 1814: 42. Remarks. Breure & Ablett (2014) have placed this taxon in the genus Bostryx on account of the smooth protoconch of the type material. However, as it cannot be excluded that this material was worn, we have examined the large series of this species in the CCP-material, and additional non-CCP-material (MNCN 15.05/20306, 20308, Coll. Hidalgo). The protoconch sculpture shows some faint axial wrinkles, irregularly spaced and mostly on the lower part of the protoconch, only becoming more densely and prominent towards the transition to the teleoconch. This sculpture is unlike those observed in Caribbean Bulimulus species (Breure, 1974) nor in other Argentinan Bulimulus species, and is somewhat similar to those observed in some Peruvian Bostryx species (e.g., Breure, 1978). Further (molecular) studies should provide more evidence for the systematic position of this species. Awaiting this, and also for the stability of nomenclature, we tentatively concur with the recent review of Cuezzo, Miranda & Constanza Ovando (2013). (  tentatively also assigned to the CCP material. The systematic position follows Cuezzo, Miranda & Constanza Ovando (2013).
The number of lots recognised as CCP material has been augmented through this study from 230 to 560 lots, totalling 3,470 specimens. Actually, this number is somewhat larger as we know from the correspondence of Hidalgo with Crosse that during the years of study of the CCP material, he gifted Crosse and some others material originating from this expedition (Breure & Backhuys, 2017). When Hidalgo started to study the CCP material, original labels seem to have been removed or lost. The example of the label with very precise locality data in the handwriting of Paz (MNCN 15.05/7344) makes one wonder if originally similar labels were present with other specimens (at least Paz could have had the opportunity of doing so). Other indications are the meticulous way in which part of the CCP members kept their diaries (Almagro, Isern, Jiménez de la Espada, and Martinez), and the detailed locality data with the botanical material of Isern (Blanco, Rodríguez & Rodríguez, 2006). It is remarkable that Hidalgo (1870: 56) in only one case wrote ''L'étiquette qui portrait la localité exacte de cette coquille a été égarée'', which could be an indication that these original labels with more precise information were provided by the collectors. Hidalgo published in several cases more precise localities than the current labels show, and the original labels may have disappeared through the flux of the collection over time.
When Hidalgo, describing a new species, had more than one specimen at hand, he appeared to have kept in Madrid the shell of which he mentioned the dimensions in the text of his publications, and sent another one to Crosse for illustration in the Journal de Conchyliologie (see e.g., Stenostylus colmeiroi). As in such cases this shell was often kept by Crosse and ended up in ''Coll. JdeC'', and consequently is now in the MNHN, these specimens were often not the ones which the author had used as 'the type'. Later authors, being unaware of this mechanism, may thus have considered this material as the 'holotype' (Fischer-Piette, 1950) or 'lectotype' (Breure, 1975), noticing at the same time that the dimensions did not match those given in the original publication. This shows once more that contextual information from early science networks can help to give a more precise interpretation when studying historical collections.

CONCLUSION
The CCP expedition yielded 245 species of land molluscs, of which 32 were new to science and described by six authors between 1866 and 2015. In total 3,470 specimens have been located in the MNCN collection that (presumably) originate from this expedition; these specimens belong to 211 species. Nearly all of the original labels have been lost, either at the initial stage of determination by Hidalgo or subsequently during the 'flux' of the collection. The publication of collection localities by Hidalgo often reveals more precise localities than the current labels suggest; the published diaries of some CCP members allowed for a check of these localities and also gives a collection date in the majoriy of cases. Research in archives has revealed that the study of this material and the publication of its results have been hampered by several obstacles. This contextual research has thus shed light on the historical collection by this Spanish expedition.